Nut



Sept. 9, 1941.

J. B. HOOD NUT Filed may 27, 1939 INVENT OR.

7 James Bruce Hood.

' ATTORNEY.-

drawing, constituting a. component oi this dis atented Sept. i941 oresJames hence E New York, N. H, Application may 2'2, 1939,, serial he.starts 3 Claims.

This invention relates to nuts, in which is included any object, of anymaterial and oi any exterior shape, having an opening in which is formeda helical groove, known as a thread. adapted to engage on an externallyscrew thresd= ed object of corresponding and constant dieter, shape andpitch.

The term pitch is indicative of the nher of threads or helical groovesper inch in length; difierent diameters coonly have threads or difierentpitches.

It is well known that nuts do frequently he come loosened from the partson which they are engaged, due to jars, vibration and other on a e suchconditions being known as loose.

in order to avoid such occurrences recourm has been made to numerous weas loch nuts, lock washers, cotter pins, etc.. etc.

It will therefore be apparent that a nut which will remain in itsadjusted position is desirable, in fact a necessity in the constructionof many mechancal structures.

It is therefore an object of this invention to provide a nut that willunfailingly cling to the part to which it is applied, irrespective orcondi tions that would loosen a nut of on :u: 1;. on *1 Theseadvantageous objects are accomplished by the novel constructionandfarrangent or the internal portion or a plain nut, as heriterdescribed and illustrated inthe w closure, and in which- Figure l is avertical sectional view of a conventional nut screw threaded inaccordance with 35 In the present invention the nut 95, shown in.

section in Figure i, has its threads formed as shown, to two distinctdiameters, the greater of -which may be regarded as standard, enteringfrom the bottom, or under face, of the nut thr approximately two thirdsof the thickness of the body, as indicated at It, whlleits upper portionis subnormal or reduced in diameter the-reduc t'ion being-but a smallfraction of aniachde 55 with the threaded u ope pen 1w on the we size ofthe nut, its tolerances and other conditions.

It is to he understood that both the reduced and stanrd portions of thenut are of uniform 5- diameter st-each portion, not taper, of the sameconstant pitch and angle oi thread.

in the v-wercial form of nut shown in Figuses 2 toe a eitum ar conditionis indicated, having like characteristics.

w The nut to is threaded throughout its entire thickness to produce astandard diameter of thread 26; thereafter the outer portion 22 of thethread is contracted, the junction being indicated at 293.

3 Nu. is scooped by fore in the upper as log a standard thread it in itsmain body and a contrscwd thread 32 in its outwardly extending aularflange or collar til, the junction, shown accentuated at 3d,substantially in the plane of the bottom of a shallow annular groove 85in the $0 upper face of the nut.

in Fie 2 the nut is has a standard diameter of thread 25 extendingapproxately to the hat of the groove ttthence the pitch diameter 22 oithe thread is slightly less than standard.

a of metal wall hacking this portlon oi the thread is shown at 25, andis proportioned to expand elastically when engaging a mating screwelement. Similarly, in Figure 4 the nut it has two pitch dieters, as inthe main body of the 'nut and as in the projecting collar or hoop 33 orreduced n 1 m: 6%82.

The recess or groove 33% adds to the length oi 4 the collar 33 andavoids having an extended collar projechon.

At 253, Figure 12, and $43 in Figure 4:, the change in pitch diameteroccurs so that the lesser diametered section of thread is whollycontained in so the expansible collar 25 in Figure 2, and S3 in l' igurei.

It is to he noted that no nut as made at prescut, so far as can heascertained, has the features .0 by this put. A nut threaded to twoparallel-pitch diameters,

each having perfect pitch and angle of thread. so made that both flanksot the thread in the upper portion make intensive pressure contact withthe same elements or an engaging screw, gives a positive holding grip,whether the nut is tightened on the work or not.

This allows for adjustment in cases where necessary without danger ofthe nut running ofli.

1 It will be obvious that ordinary nuts, when tightened,'bear only onone flank of the threads. There is no deformation of the thread, eitherin the angle or pitch, such as occurs with bumped" threaded elements,which gives spot, or at best,

line contact; thus the intensity of pressure hecomes excessive or causespermanent deformation of the elements, as compared with the much greaterareas of contact and low pressure within the elastic limit of thematerial obtained in the nut disclosed in Figure 4.

From the foregoing it will be seen that simple 20, i and practical nutshave been disclosed, their screw threads presenting an eflicientlgrip,dispensing with all extraneous elements, inexpensive distinguished fromthe lower portion by havin a lesser but constant pitch diameter, bothportions being continuous and having in common the same thread i'orm andthe same constant pitch, and both being concentrically parallel to thenut axis.

2. A nut having its threads formed into two continuous portions, oneportion being of a lesser but constant pitch diameter than the other, acircular band composed of the lesser pitch diameter threads as itsinside surface and a ring of the metal extending immediately outwardcircumferentially from the said portion of thread, the outer limit ofsaid ring forming the outside surface 01' said band, the same constantpitch and the same thread form being maintained throughout the whole ofthe nut thread, said thread being throughout its entire lengthconcentrically parallel to the nut axis.

3. A nut having its threads formed into two continuous portions, oneportion being of a lesser but constant pitch diameter than the other andhaving an annular groove concentric with the said lesser pitch diameterthread whose inside wall forms the outside surface of a metal band whoseinside surface is the lesser pitch diameter thread, the same constantpitch and the same thread form being maintained throughout the whole ofthe nut thread, said thread being throughout its entire lengthconcentrically parallel to the nut axis.

JANIES BRUCE HOOD.

